Stone gained her earliest acting experience performing with the Valley Youth Theatre in Phoenix. During her freshman year in high school, she persuaded her parents to allow her to move to Los Angeles to pursue an acting career. She and her mother took an apartment there, and Stone was homeschooled between auditions. Her first role came in 2005 when she landed the part of Laurie Partridge in The New Partridge Family, a pilot for a proposed television series.
More TV roles followed, and in 2007 Stone made her film debut acting with Jonah Hill and Michael Cera in the teen comedy Superbad. Stone continued to appear in similar movies, of which the most notable was the horror comedy Zombieland (2009). The following year Stone achieved her first starring role, in the teen comedy Easy A (2010), as a high school girl who pretends to have slept with a gay friend and various other social outcasts in order to give them a patina of coolness. The movie proved to be her breakthrough.
Stone appeared with Ryan Gosling in the well-received romantic comedy Crazy, Stupid, Love. (2011) and then was cast in the role of Skeeter, the aspiring author who interviews African American housemaids (played by Viola Davis and Octavia Spencer) about their experiences working for white families in Tate Taylor’s The Help—her first experience outside comedy.